Arc-lamp.



H. E. DAVIES.

ARC LAMP.

APPLICATION rum) APR.12, 1910.

1,106,789, Patented Aug. 11, 19%

Fig. i.

HENRY E. DAVIES, OF WEST NEW YORK, NEW JERSEY.

ARC-LAMP.

Specification of Letters Patent.

Patented Aug. 11, 1914.

Application filed April 12, 1910. Serial No. 555,098.

To all whom it may concern:

Be it known that I, HENRY E. DAVIES, a citizen of the United States of America, re siding at West New York, in the county of. Hudson and State of New Jersey, have invented certain new and useful Improvements in Arc Lamps, of which the following is a specification.

My invention relates to are lamps and particularly to the electrode feed mechanism, the object of my invention being to provide a simple and effective mechanism whereby a steady arc is maintained during the operation of the lamp.

In the accompanying drawings, Figure 1 is a. broken side elevation of portion of an arc lamp showing my invention embodied therein in one form; Fig. 2 is a broken elevation at right angles thereto; Fig. 3 is a perspective of details of the mechanism, detached; and Fig. 4 is a diagram of the circuit through the lamp.

The mechanism commonly employed in many are lamps to keep the electrodes in proper position to maintain the arc during the operation of the lamp is defective in that the feed is uneven and jerky and furthermore the escapement mechanism by which the feed is controlled is not positively actuated, so that frequently more than the desired number of teeth on the ratchet are slipped by the pawl, with the result that the carbons actually come into contact and injury to the lamp is thereby rendered imminent by reason of the excessive current which immediately flows through the lamp. Furthermore the slip of the feed chain is generally taken up entirely and directly by the movable electrode so that even when the intended amount of chain is fed a sudden variation in the distance between the electrodes results. All danger of this is eliminated in the present mechanism by which not only is a positive engagement of the pawl with the escapement wheel secured, but upon the slip of a tooth the sudden lengthening of the chain is taken up by an interposed member and the fall of the carbon is gradual, since the weight of the latter is to a great extent counterbalanced by this interposed member.

In the arrangement illustrated the invention is adapted to a lamp burning vertical carbons, though the mechanism may obviously be adapted to various other forms of lamps. The upper carbon A is clamped to the cross piece B which is guided as usual on the spacing rods C, D extending between the upper E and lower (not shown) frame plates. The feed chain F by which the cross piece B is suspended passes up over the pulley G thence down and beneath the pulley H at the top of the core I of the solenoid J and up over the feed pulley K, the other end of the length of chain being fastened at any convenient point, such as book L. Fast on the spindle is of the feed wheel K, is mounted the ratchet wheel M. The pawl O, which engages this ratchet wheel, while freely mounted on the spindle 0, is subjected to the rocking movement of the lever I through the lug p upon which the said pawl 0 normally rests by reason of the eccentric location of its pivoting point. The lever P is also pivoted on the spindle 0. A link Q connects the other end of said lever P with the solenoid core I. Upon the drop of the core I the pawl O is obviously pulled into positive engagement with the teeth of the escapement wheel and thus serves to positively and certainly arrest the same. The variable weight R carried at the lower end of the core I is added to adjust the normal current of the lamp. The rise of the core is of course retarded by the increase of current in the solenoid as the electrodes approach each other.

The lamp circuit is illustrated in the diagram Fig. 4 entering the lamp at 00 passing through the solenoid J to the arc and thence out at y. Any other suitable arrangement of the solenoid may be employed.

The operation of the device is as follows: The upper and lower electrodes being in contact and the core I being slightly out of the solenoid J, the lamp current is switched on. This energizes the solenoid and the core is drawn down, thus lifting the upper electrode A and starting the are. As the electrodes burn away under the influence of the arc, the arc lengthens, and the amount of current flowing through the solenoid being lessened th core rises until the pawl O slips a tooth on the escapement wheel M. The feed of the chain by the consequent rotation of the wheel K is at once taken up practically completely by the downward movement of the solenoid core I since the release of the escapement removes half of the support of the core and the pawl O is thus brought positively into engagement with the next tooth of the escapement wheel and prevents any accidental excessive feed of the chain. Even if the solenoid core were very much lighter than the electrode, it would still drop first and the electrode would raise it gradually by reason or" oyerbalancing weight. Since the slip of the chain is taken up by the core I, the electrode A remains unailected until by reason of its overweight it gradually sinks, lifting the core until the increased current flowing through the solenoid establishes a balance. it will thus be seen that not only is the positive engagement of the escapement, and thus positively limited feed, secured by the present ar angement, but that the sudden drop of the upper electrode upon the slip of the pawl is avoid ed, and on the contrary a gradual reestab lishment of the proper arc length is secured.

To trim the lamp, the solenoid core I may be first lifted to tilt the lever P and thus free the detent 0 from the escapement wheel and the chain then pulled to lift the elec-l trode bar B for the insertion of a fresh carbon. Obviously the mechanism shown may be variously modified within the scope of the appended claims, not only in detail but also in arrangement to meet the needs of lamps of other types, the lamp shown being merely the simplest embodiment of my invention for illustrative purposes.

I claim as my invention:

1. in an arc lamp, an electrode feed com prising an escapement mechanism, a meme ber arranged to take up the slack in the feed chain upon the slip of a tooth by the pawl and means in connection with said take-up member for bringing said pawl into positive reengagement with the escapement wheel upon the slip of a tooth on the latter by said pawl, substantially as described.

2. In an arc lamp, an escapement electrode feed comprising a ratchet-controlled "feed wheel, a flexible suspension member magnetically controlled member acting on;

said suspension member intermedia e said electrode and feed wheel, and a connection between said magnetically controlled member and the pawl for the ratchet feed wheel whereby upon the movement of said 1nagnetically controlled member in one direction the said pawl is brought positively into engagement with its ratchet, in combination with an electromagnetic winding", the action of which is controlled by the arc circuit, for controlling the position of said magnetically controlled member, substantially as described.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses.

HENRY E. DAVIES.

Witnesses CHAS. M. TRAINN, ALBERT G. Vnrrorr.

denies of this patent may be obtained for five cents eacluby addressing the Commissioner of Patents, Washington, D. G. 

